ZFIN ID: ZDB-PUB-090505-14
Pannexin1 in the outer retina of the zebrafish, Danio rerio
Prochnow, N., Hoffmann, S., Vroman, R., Klooster, J., Bunse, S., Kamermans, M., Dermietzel, R., and Zoidl, G.
Date: 2009
Source: Neuroscience   162(4): 1039-1054 (Journal)
Registered Authors: Kamermans, Maarten, Zoidl, Georg
Keywords: pannexin, retina, electrical synapse, horizontal cell
MeSH Terms:
  • Animals
  • Calcium/metabolism
  • Cell Line, Tumor
  • Connexins/biosynthesis*
  • Connexins/genetics
  • Dendrites/metabolism
  • Gap Junctions/metabolism
  • Intracellular Space/metabolism
  • Ion Channel Gating
  • Ion Channels/biosynthesis*
  • Membrane Potentials
  • Mice
  • Patch-Clamp Techniques
  • Retinal Photoreceptor Cell Outer Segment/metabolism*
  • Retinal Photoreceptor Cell Outer Segment/ultrastructure
  • Zebrafish/metabolism*
  • Zebrafish Proteins/biosynthesis*
  • Zebrafish Proteins/genetics
PubMed: 19409451 Full text @ Neuroscience
In the retina, chemical and electrical synapses couple neurons into functional networks. New candidates encoding for electrical synapse proteins have recently emerged. In the present study, we determined the localization of the candidate protein pannexin1 (zfPanx1) in the zebrafish retina and studied the functional properties of zfPanx1 exogenously expressed in N2a cells. ZfPanx1 was identified on the surface of horizontal cell dendrites invaginating deeply into the cone pedicle near the glutamate release sites of the cones, providing in vivo evidence for hemichannel formation at that location. This strategic position of zfPanx1 in the photoreceptor synapse could potentially allow modulation of cone output. Using whole cell voltage clamp and excised patch recordings of transfected N2a cells, we demonstrated that zfPanx1 forms voltage activated hemichannels with a large unitary conductance in vitro. These channels can open at physiological membrane potentials. Functional channels were not formed following mutation of a single amino acid within a conserved protein motif recently shown to be N-glycosylated in rodent Panx1. Together, these findings indicate that zfPanx1 displays properties similar to its mammalian homologues and can potentially play an important role in functions of the outer retina.